1. Field of the Invention
The present invention relates generally to an information processing apparatus, an information processing method, and a system, and particularly to an information processing apparatus that provides control data for forming visual information to an apparatus that forms visual information on a recording medium by irradiating laser light.
2. Description of the Related Art
Technology for writing characters and symbols on a sheet medium such as paper using laser are practically applied in various fields. Such technology for writing characters on a sheet medium may facilitate drawing characters on container labels used at factories and other sites, for example. In the context of applying this technology to container labels, for example, the destination of goods and/or the name of goods may be printed on the container labels implementing this technology to reduce manual or mechanical labor for replacing the container labels (see, e.g., Japanese Laid-Open Patent Publication No. 2004-90026). Japanese Laid-Open Patent Publication No. 2004-90026 discloses a relay lens system that transmits an image using a laser beam entered from one end to the other end of plural lens systems made of plural flexible joints.
Also, practical applications are developing for rewritable thermal paper that can have objects drawn and erased multiple times. For example, in the context of applying this technology to containers used in product distribution, since the destination of a container is not necessarily the same each time it is dispatched, the above technology may be used to erase characters drawn on a label so that new characters can be drawn on the same label. In this way, the need to replace the label may be reduced.
FIG. 1 shows an exemplary label having characters and other objects drawn thereon. The label has plural objects such as numbers, characters, figures, and a barcode drawn thereon. When drawing characters, laser is condensed by a lens into a focused beam so that even intricate characters may be drawn. When drawing characters and other objects using laser, the laser irradiating position is controlled so that strokes (lines) of a character are drawn by the laser beam.
FIGS. 2A and 2B illustrate an example in which the letter T is drawn on thermal paper. FIG. 2A shows an exemplary printout of the letter T output by a printing apparatus. The letter T is made up of two strokes, one lateral line and one vertical line. In the case of drawing this letter T using laser, laser irradiation is controlled to draw the above two strokes.
FIG. 2B shows exemplary pairs of starting points and end points, (s1, e1) and (s2, e2), of the two strokes making up the letter T. A writing control apparatus for controlling the laser irradiating position may move the laser irradiating position to the starting point s1 without irradiating any laser by adjusting the position of the laser beam using a galvano mirror, for example. Then, the writing control apparatus may start laser irradiation (may simply be referred to as “laser ON” hereinafter) and move the beam from the starting point s1 to the end point e1.
Then, the writing control apparatus may stop the laser irradiation (may simply be referred to as “laser OFF” hereinafter) and move the laser irradiating position to the starting point s2 without irradiating any laser. Then, the writing control apparatus may start laser irradiation and move the laser beam from the starting point s2 to the end point e2. In this way, the two strokes making up the letter T may be drawn on the thermal paper. That is, visual information may be formed by transmitting laser energy to the thermal paper while continuously changing the transmitting position of the laser.
When drawing characters and other objects on thermal paper as described above, the writing control apparatus may control laser irradiating operations of a drawing apparatus such as a laser irradiating apparatus using a control command (drawing command) directing “laser ON from starting point to end point and move laser beam,” for example.
FIG. 3A shows an exemplary drawing object including a character and a figure. FIG. 3B shows an exemplary control command used by the writing control apparatus. It is noted that the references ln, W, Sp, and Ep in the control command shown in FIG. 3B represent the following:
ln: line number (stroke number)
W: laser ON/OFF (where “1” denotes ON and “0” denotes OFF)
Sp: starting point coordinates
Ep: end point coordinates.
It is noted that the coordinates are represented as (X, Y) where X designates a position in the horizontal direction and Y designates a position in the vertical direction. The coordinate value of X increases as the position moves rightward. The coordinate value of Y increases as the position moves upward. It is noted that the above manner of defining a coordinate point is merely an illustrative example and other methods may be used as well.
In drawing an object such as a character or a figure (also referred to as “drawing object” hereinafter) on thermal paper, a control command for controlling the laser beam has to be generated based on the drawing object. Also, additional processes such as rotating a character from its original position, removing overlapping portions between lines, and setting up other items of information must be contemplated as well. In this regard, drawing object data that is to be converted into a beam control command is preferably in vector data format.
FIG. 4 is a diagram illustrating exemplary drawing object data for drawing a triangle on thermal paper. In the following descriptions, an apparatus that generates vector data and/or a scanning command is referred to as “image processing apparatus.”
FIG. 4 (a) illustrates data that is supplied to the image processing apparatus by a user. The user may designate the coordinates of the vertices of the figure (e.g., triangle) to be drawn. The coordinates may also be supplied by a file created by an application. In the case of drawing a triangle, three coordinate points vp are designated.
FIG. 4 (b) illustrates exemplary vector data generated by the image processing apparatus. That is, three vectors (stS, stE) connecting the vertices are generated. The direction of the vector is not particularly limited to a certain direction, but may be in the clockwise direction, for example. By converting the coordinate data into vector data, internal processes (e.g., rotation, scaling, filling, and drawing order designation) may be facilitated, for example. It is noted that stroke information is not limited to such coordinate data and may also include information on the drawing power and width, for example. In the illustrated example, one vector includes a starting point (stS) and an end point (stE).
FIG. 4 (c) illustrates an exemplary scanning command generated by the image processing apparatus. The image processing apparatus performs internal processes on the vector data, and generates a laser scanning command including markers after completing desired processes. Then, the writing control apparatus reads the scanning command and draws the corresponding figure designated by the user on thermal paper.
It is noted that in some cases, the user may wish to draw not only the outline of the figure but also fill in the interior of the figure (also referred to as “filled figure” hereinafter). In this case, once vector data of the drawing object is obtained, appropriate image processes may be performed before generating a laser scanning command.
FIGS. 5A-5C are diagrams illustrating an exemplary manner of drawing a filled figure. In FIG. 5A, the user inputs coordinates of vertices A-E of a pentagon. In FIG. 5B, the image processing apparatus generates vector data by extracting horizontal lines extending from one side to another side of the pentagon using the coordinates of the vertices A-E. It is noted that the vectors of the vector data are spaced apart by a predetermined distance (pitch ph).
In FIG. 5C, the image processing apparatus generates a filled image by controlling the beam position of laser according to the scanning command.
Techniques for filling in an enclosed region in the above described manner are known (see, e.g., Japanese Laid-Open Patent Publication No. 61-52737). Japanese Laid-Open Patent Publication No. 61-52737 discloses a display device that smears out (fills in) a concave polygon by extracting plural convex polygons from the concave polygon.
However, in the case of implementing the technique disclosed in Japanese Laid-Open Patent Publication No. 61-52737, generating the data for filling in the polygon may be quite time-consuming. Although Japanese Laid-Open Patent Publication No. 61-52737 does not disclose a specific manner of generating the data for filling in the polygon, if the data were to be generated by simply searching the point of intersection between a horizontal vector and one side of the polygon, a significant amount of processing time may be required to generate the data.